Andrzej Tomczyk

Experimental Fly-By-Wire Control System for General Aviation Aircraft

In this paper, a proposal of employing an intuitive, human-centered, simplified software-based flight control system in general aviation aircraft has been presented. Airplanes equipped with such a flight control system with belong to a new class of general aviation aircraft with improved safety and efficiency handling properties – Facilitated Airplane (FA) or Simple Flying Airplane (SFA). The proposed method of aircraft control differs from traditional solutions. It proposes a different pilot role and different aircraft handling qualities. It is assumed that the aircraft is automatically controlled; pilot makes decisions and introduces corrections when necessary. Pilot displaces sidestick and controls the airplane indirectly, via forming filters, handling quality processor and stabilization control system. Depending on phase of flight, pilot enters flight parameters (for example: flight path, heading, altitude) into the system or manually controls aircrafts attitude and airspeed by manual control deflection. Algorithms that calculate and perform control have been equipped with built-in testing mechanisms, which minimize the possibility of exceeding operating limitations, both under automatic and manual control. The control system, without pilots participation, counteracts the results of external disturbances (for example, air turbulence), dampens undesired oscillations (for example, dutch roll oscillations), and stabilization of flight parameters: bank angle or heading, flight altitude, pitch angle or airspeed. Flight control system is equipped with diagnostic subsystems to ensure the desired level of reliability. New design concepts allow improvements in operating properties of already existing and newly designed executive aircraft, as well as establishing a higher level of flight safety.

Concept for Simplified Control of General Aviation Aircraft

In this paper, a concept is presented for a fly-bywire (FEW) control system for general aviation aircraft. Fly-by-wire implies that the cockpit controls are not mechanically linked to aerodynamic surfaces but are used only as the commands generator for the automatic flight control system. The objective of the proposed concept for the control system is to assist pilots with limited aviation training by: 1) automatic stabilization of the aircrafts attitude, altitude, airspeed, and heading and 2) decoupling of the flight controls. Decoupling of the flight controls implies that a single cockpit control can independently control a single flight parameter. An example of this would be moving the control yoke/stick fore and aft results in a change in pitch angle without changing air speed, thus simplifying the control of the aircraft. It is in simplification of control to assist pilots with limited training that the proposed concept is particularly useful in general aviation.

Safety enhanced digital flight control system

Purpose – The purpose of this paper is to describe the general idea, design, and implementation of control system for general aviation aircraft which reduces pilot workload.Design/methodology/approach – Proposed indirect flight control system framework is intended to simplify piloting, reduce pilot workload, and allow low‐end general aviation aircraft to operate under deteriorated meteorological conditions. Classical control theory is used for the design of the flight control laws. Although not inherently robust, controllers with classical control logic are made sufficiently stable using a correct and updated controller structure.Findings – Despite controversies between perception of a modern manned aerial vehicle and limitations imposed by legacy airworthiness codes it is shown that a pilot workload reducing system can be successfully implemented onboard of a low‐end general aviation aircraft.Research limitations/implications – Hi‐level control laws and optimization of handling qualities can lead to unfa...

In‐flight tests of navigation and control system of unmanned aerial vehicle

In this paper, results of the flight‐testing of an unmanned aerial vehicle (UAV) flight control system are presented. APC‐4 “SkyGuide” autonomous navigation and control system, designed and developed by the research team of the Department of Avionics and Control at Rzeszow University of Technology, has been tested. Properties of this flight control system, as well as selected results of the in‐flight tests conducted on board of the PZL‐110 “Koliber” aircraft, are presented. Results obtained confirm that design assumptions of the navigation and control system and research methodology have been appropriate and APC‐4 autopilot can be used on UAVs board.

Algorithms of Measurement System for a Micro UAV

The article presents a measurement system for a micro UAV designed at the Department of Avionics and Control Systems of Rzeszów University of Technology. Since the project is based on earlier projects, e.g.[[[[1[[[1, the introduction begins with their short presentation [they are mentioned in the introduction firs. Then, the current project is discussed. The major objective of the project is to create a miniature autopilot cooperating with navigation units, data transmission units and measurement units. The system is based on Polish technological solutions. The autopilot is designed as a single unit, however the system is open and it allows you to use different elements. The system development is also possible. In-flight testing will be realized with the use of two unmanned flying platforms equipped with an electrical engine and a piston engine. The total mass of the platforms is 5 kg and 25 kg respectively. The article presents the structure of the control and navigation system and then, the structure of the measurement system. The measurement units consist of a GPS receiver, an attitude and heading reference system (AHRS) and an air data computer (ADC). Similar configuration is used in other micro UAV solutions, such as Micropilot or Kestrel. Then, algorithms of the measurement system are described. Navigation is based on GPS data with a DGPS (Differential GPS) advanced module. If the measurement information is complete, GPS data are used to correct measurements from other units. The system estimates wind disturbances and calculates accelerometers errors. In the case of missing GPS signals implementation of low-cost sensors may lead to significant measurement errors, and hence navigation only by means of the INS is impossible. In such a case, navigation is realized with the use of an inertial navigation system (INS), the magnetic heading measurement and ADC. AHRS unit algorithms use quaternion algebra for attitude calculation. For correction, complementary filtering is implemented [, [. The correction signal for the attitude (pitch and roll angles) is calculated with the use of acceleration measurements. Measurements of accelerations and yaw rates are used for the correction switching mechanism, since in dynamic states signals calculated from accelerations cannot be used for correction. Heading is corrected by means of magnetic heading measurement. ADC algorithms are based on typical aerodynamic dependences.

Testing of the attitude and heading reference system

Rzeszow University of Technology has undertaken the task of designing and providing of equipment to a flying laboratory. This paper presents basic design principles of the Inertial Reference Unit (IRU) which employs measuring signals from the Fiber Optic Gyros (FOG), accelerometers and electronic compass module. A microcomputer follows the algorithm of complementary filtration for of calculating the Euler angles for the aircraft attitude (pitch, roll and heading), angular rates, and linear accelerations. The correction systems that minimize error of the steady‐state measuring have been employed. The results of computer simulations, lab tests and selected flight tests have also been presented. The Inertial Reference Unit μIRU‐1 was tested in flight on board of the general aviation aircraft PZL‐110 “Koliber”. It has been confirmed that metrological properties of the system are appropriate for the purposes of teaching process. Currently, a modified version of the unit is being prepared. The new IRU is planned as a main reference unit for integrated flight control system of general aviation aircraft.

Simple virtual attitude sensors for general aviation aircraft

Purpose – This paper aims to present a proposal of a simple analytical redundancy method using for virtual attitude reference system design. The main idea of the project is applied typical on‐board general aviation aircraft equipment for solving pitch and bank angles.Design/methodology/approach – The presented solution is based on satellite navigation and air data computer signals, which are independent from basic attitude and heading reference system. The concept described is related to the kinematics relations and aerodynamic forces formulas.Findings – The paper shows that the virtual attitude sensors are used by failure detection and reconfiguration subsystem and as a standby attitude reference system for general aviation aircraft equipped with augmentation control system applied for improving safety and efficiency handling qualities of aircraft.Originality/value – This solution allows improvements in operating properties of already existing and newly designed executive aircraft, as well as establishin...

Flight Simulator as a Tool for Flight Control System Synthesis and Handling Qualities Research

At the Department of Avionics and Control Systems problems of aeronautical control systems have been dealt with for years. Several different kinds of aeronautical control systems have been designed, prototyped and tested. These control systems are intended for general aviation aircraft and unmanned aircraft. During all research projects computer simulations and laboratory tests were made. However, since in some cases such tests were insufficient, in-flight tests were conducted leading to a series of reliable results. The in-flight tests were made with the use of M-20 Mewa aircraft (autopilot for a GA aircraft) and PZL-110 Koliber aircraft (control system for UAV and indirect flight control system for a GA aircraft). Nevertheless, in-flight testing is very expensive and problematic. To avoid some problems appearing during in-flight tests and their preparation, a simulator – which is normally used for professional pilot training – can be used. The Aviation Training Center of the Rzeszów University of Technology possesses the ALSIM AL-200 MCC flight simulator. We have started preparing this simulator for the research. It is possible to control the simulated aircraft with the use of an external control system. The solution proposed enables testing the aircraft control algorithms, indirect control laws (e.g. control laws modifying handling qualities), as well as testing and assessment of the students’ pilotage skills. Moreover, the solution makes it possible to conduct tests connected with aircraft control, crew management, crew cooperation and flight safety. The simulator allows us to test dangerous situations, which – because of safety reasons – is impossible during in-flight testing. This paper presents modifications to the simulator’s hardware and additional software, which enable the described research.

A proposal of handling qualities shaping for general aviation aircraft

A proposal of the perspective solution of the general aviation aircraft control system is presented. The objective of the proposed concept for the control system is to assist pilots with limited aviation training by: automatic stabilization of the aircrafts attitude, altitude, airspeed, and heading and decoupling of the flight controls. The structure and main functions of the control system is presented, and method of control laws synthesis is proposed. Flight control system is based on the model‐following design technique. Two kinds of flight control systems are taken into consideration. The first solution is based on the optimal full‐state feedback controller, the second one is the simplified controller, using the easy observed states for feedback loop only. The project calculation of the flight control system for PZL‐110 “Koliber” aircraft, computer simulations and preliminary flight testing results will be presented.

The flying laboratory for aeronautics students' education

Purpose – The main targets of the work are analysis and simulation of flying laboratory performance. In particular, synthesis of control system for handling qualities change and evaluation in flight are taken into consideration.Design/methodology/approach – Modification of handling qualities is obtained by applying indirect flight control system (FBW). The properties of the optimal controller are calculated through the indirect (implicit) model‐following method. In particular, the modified version based on the computer simulations is used.Findings – Calculation and simulation concern the synthesis of desired handling qualities of the general aviation aircraft PZL‐M20 “Mewa” equipped with indirect (FBW) experimental flight control system. Results of the simulation show that the flying laboratory has the same properties as modeled aircraft, and it is possible to say that handling properties concern attitude orientation of the experimental aircraft is similar to modeled commuter aircraft.Practical implicatio...